2002 Civic EX bought used. Drove car two weeks and realized hack mechanic that worked on car prior to purchase stripped out alternator bracket and fried ECU. This is a California low emission car. Put first ECU box in and would not work. Realized replacement box came from federal emissions car. Researched and found used ECU box with numbers 37820-PLM-L54 pulled out of California car also. The replacement box number matches original box number. Replacement box will not start car. Does anyone have any ideas or come someone help me please!

 

Have you had the immobilizer matched at the dealership? If not, that'll prevent the engine from firing.

 

What the hell is a immobilizer and where would this be found? Sorry to sound so stupid, but I don't know much about the electronics on these on these cars. I can do most anything else. Thanks for any help.

 

There's three parts to the immobilizer. Its a fail-safe to prevent theft.

Components:
1. Key (there's a transponder in it)
2. Immobilizer Ring - your key cylinder on the steering column has a receptor ring around it
3. In the ECU - The ECU is programmed to to match the key and immobilizer ring to the ECU.

Like I stated before, you'll need a dealership to reprogram that. Its not something you can DIY.

 

Well thank you very much for all of the info, it looks like the next trip is to Honda

 

When you say "not start the car" do you mean cranks and not fires up the engine? Just cranking and no fire means potential immobilizer issues as mentioned from toyomatt84 (he knows his Hondas ).

 

I also know how to make a wicked tasty chili. But that's not really all that helpful here.

 

Took the car to friend of a friend at the dealer and he hooked me up. He programed the immobilizer, key, and ecu. Winner Winner chicken dinner! It has been running a week now, thanks guys.

 

No problemo!

 

Great site and good info here, not new to working on cars just computerized cars.